(Settings), Data range
mode: *User defined, (OK). Now you can enter new Min and Max

values and (Apply).

Return (Settings) to Data
range mode: *Data range before looking at another map.

We started with initial
velocity information, usually from well checkshot survey or seismic
stacking velocities. We had 2 data points in a velocity survey.
Subsequently, we refined this to 5-8 data points, which tied all
sonic logs and synthetics to the seismic reflectors. The velocity
gradients in the Moosehead seem to be well-behaved, most seismic
surveys require layer by layer velocity determination with some
layers requiring velocity gradients across the survey. Accurate time
to depth conversion is very difficult. Consider yourself lucky if you
can predict well tops within 2% of actual depth. That may sound
reasonably good, but it is still 200 feet in a 10,000 foot well.
Drillers hate that kind of error, especially when you are
anticipating a core point or an overpressured zone which could cause
a blowout.

Note the thinning in time
at the well locations. This indicates a paleo high where the wells
were drilled. If the wells were discoveries, this might support
drilling additional locations in the southwest corner of the 3D and
development locations near wells #1 and #2.

As one would expect, the
fault graben in the WAB Group distorts the isochron map.

(Import Wells from
Interpretation), (OK), +Operator name in Line 1:, +Well number in

Line 2:, (Close).

Attribute Analysis and
Mapping

Recommendation for
Attribute Analysis: There are some attributes which are logically
predictable such as a gas sand producing a bright spot apparent on an
amplitude attribute map, or a high frequency response of 2 formations
close to each other resulting in a high frequency doublet instead of
a lower frequency single reflector when only 1 formation is present.

In general, because of
the great number of attribute computations available and the
uncertainty of how each is computed, it is usually most productive to
generate all attributes and focus on explaining those which support
your interpretation.

PDW Tools >Surface
Calculator. Study Attribute options. You can find an explanation of
each

attribute by moving the
mouse to that attribute then RightClick. (Attribute Details).
(Close).

Now
Rotate. Interpretation time to play. Remember to scroll through
seismic and watch 3D View.

Interpretation
Break: Until End of Class

Experiment with 3D
View

Homework Due 2/6/2003
at Beginning of Class:

Generate
and print a Time Structure contour map and a Depth contour map for
the Fort Vermilion Formation. Generate and print an Isochron map and
an Isopach map for the WAB Group to Fort Vermilion interval. Black
and white maps OK.

Generate and print [can
be black and white] a single 3D view which contains one 3D line, one
2D line, two horizons with Time Surface Overlays, one timeslice, one
fault plane, and all three wells.